I guess you can do it. Early ponds were dug by using horses. Other than your life, you don't have much to lose. Working on steep slopes is scary.
Thought of renting a dozer? Every little boy, no matter what our age, has wanted to rent a dozer, clear land, and dig holes. However, it's not very efficient or cost effective. A real dozer driver can accomplish more in one hour than I could in 2 days.
The last time I mentioned this dozer idea to my wife, she just rolled her eyes and walked away.
If you do it, no matter what you use, get lots of life insurance. All machinery can kill you without ever shedding a tear.
Of course I would try it.